Improvement in pavements



I. B. POTTS.

PAVEMENT.

Patented Jan.11, 1876.

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UNITED4 STATES ISAAC B. POTTS, OF COLUMBUS, OHIO.

IMPROVEMENT IN PAVEMENTS.

Speeieation frming part of Letters Patent No. 172,167, dated January 11, 1876; application tiled i December 31, 1874.

To all whom it may concern Be it known that I, ISAAC B. PoTTs, of Golumbus, in Franklin county, and State of Ohio, have invented an Improvement in Pavernents, of which the followingis a specification:

This invention is designed to secure a more permanent roadway of concrete or asphalt surface than has heretofore been obtained; and

l it consists in a bed of sand rounded from the street to a proper depth below the upper i edge ot' the curbs A, then surface it' with sand or gravel B, rounded to the desired profile, to

form a center, as it were, on which to build an arch formed by setting a course of blocks of stone, O, arranged edgewise and parallel with the line of road, so as to forln a continuous arch between the curbs A. The crevices between the blocks C, and irregularities on their surface, are then to be filled with tar, asphalt, or other suitable grouting, to consolidate the arch, and forni an approximately level surface. The substructure thus formed is then to be surfaced with a finishing-course, D, ofcoucrete, asphalt, or other suitable composition best adapted to the climate and locality' in which it is to be used, and that will adhere to or combine with the grouting of the substructure.

By thus building the substructure, it will be evident that the' composition surface will not be as liable to depression, and consequent cracking andY destruction, as when laid `on a rubble or brokeustone foundation, which has no supporting quality in itself, being sustained entirely by the earth and sand beneath.

I am aware that acobble-stone pavement, set in the ordinary manner, and having the interstices between ythe stones filled with grouting of asphalt or concrete to render it impervious to moisture, has been devised before; but this vdoes not constitute what is known as a concrete pavement neit-her can a substructure constructed of cobble-stones possess the property of an arch, although it may be in that forxn. This, therefore, I do not claim.

Having thus described my inventin, its construction, and advantages, what l claim, and desire to secure by Letters Patent, is

A roadway constructed with a bed of sand rounded fron; curb to curb to the desired profile, and a course ot' stone blocks set edgewise and parallel with the line ot'. road, so as to form an arch betweenthe curbs, in combination with a filling and leveling course of tar, asphalt, or other gronting, and a surfacing-course of concrete or other suitable cornposition, substantially as specified.

.A ISAAC B.. POTTS. Witnesses:

GEORGE A. ATKINSON,

` O. B. THOMPSON.

PATENT OEEICE. l 

